Rashi on Exodus 39:1/רש"י על שמות ל״ט:א׳

1ומן התכלת והארגמן וגו׳ AND OF THE BLUE PURPLE AND OF THE RED PURPLE etc. — But there is no mention of linen here. From this fact I derive (cf. Rashi on Exodus 31:10) that these בגדי שרד mentioned here were not identical with the garments of the priests, for there was linen in the garments of the priests. But these were the cloths with which they covered up the holy vessels at the time of removing and packing up the articles in the Tabernacle when they set out on their journeyings which indeed had no linen in them.